ProtologueCandollea 16: 365 (1958).FamilySterculiaceae (APG: Malvaceae)
Origin and geographic distributionDombeya ambongensis is endemic to Madagascar, where it occurs in the western and southern parts of the country.UsesThe bark yields a good fibre used for making rope and for coarse weaving. Ropes made from this fibre are used for pulling heavy loads. The fibre was formerly used for tying together pieces of frameworks.PropertiesThe bark fibre is said to be particularly strong. The wood is white and soft, and not much used.BotanyShrub or small tree up to 10 m tall; branches rounded, bark grey, glabrous, striate, with round, reddish lenticels. Leaves alternate, simple; stipules triangular, up to 0.5 mm long, caducous; petiole 5–12 mm long, cylindrical, glabrous; blade ovate, up to 11 cm × 4 cm, base obtuse, apex long-attenuate, margin wavy, both surfaces glandular, upper surface glabrous or hairy, lower surface glabrous, palmately veined with 5 basal veins, venation prominent, especially below. Inflorescence an axillary umbel, glandular, glabrous, 2–9-flowered. Flowers bisexual, regular, 5-merous; pedicel slender, 12–22 mm long, articulate above the middle; epicalyx bracts 3, ovate, c. 1 mm long, brown, caducous; calyx deeply 5-fid, 8–10 mm long, lobes lanceolate, 3–4 mm long, apex acute, densely glandular outside, glabrous, more or less reflexed; petals free, obovate-elliptical, 5–10 mm × 2–4 mm, white; androecium crown-shaped, stamens 15, staminal tube 0.5–1.5 mm long, filaments free or connate above the crown, unequal, 2–6 mm long, usually alternating by (2–)3(–4) with 5 staminodes 1.5–2.5 mm long, staminodes sometimes absent; ovary semi-inferior, hairy, stylar column 1.5–2 mm long, with 2 branches 0.5–2 mm long. Fruit a loculicidal capsule.Dombeya comprises about 200 species, mainly distributed in Madagascar, with about 20 species in mainland Africa and 14 in the Mascarenes. Revisions of the genus have been carried out for mainland Africa and the Mascarenes, but not for Madagascar, and the number of species described for Madagascar is possibly too high.Many other Dombeya species endemic to Madagascar are used as fibre plants. The bark fibre of Dombeya amplifolia Arènes is made into rope and woven into cloth. The bark of Dombeya antsianakensis Baill., a small tree up to 16 m tall, yields a good fibre used for making rope and coarse textiles. The fibre is easy to prepare, especially that of young plants. It is usually extracted after retting and combed. The bark was formerly made into barkcloth. The bark fibre of Dombeya australis Scott-Elliot, a shrub or small tree up to 14 m tall, is used by fishermen use for threading and transporting their catch. The wood of this species is used for construction. Dombeya baronii Baker, a shrub, yields a good cordage fibre, of which often a prepared stock is kept. The fibre is also used for weaving cloth. Young, thin, flexible barks give the best fibre. The fibrous bark of Dombeya befotakensis Arènes, a small tree up to 12 m tall, is used for tying. The bark was formerly made into barkcloth.EcologyDombeya ambongensis occurs from sea level up to 850 m altitude in dry forest and forest remnants, on sandy and rocky soils.ManagementDombeya ambongensis used to be multiplied by cuttings.Genetic resources and breedingIt is unknown whether Dombeya ambongensis is threatened by genetic erosion.ProspectsDetailed and quantitative information on the fibre properties is lacking, but Dombeya ambongensis seems a useful local source of fibre, as the fibre is recorded to be strong, and the species used to be propagated by man.Major references• Arènes, J., 1959. Sterculiacées (Sterculiaceae). Flore de Madagascar et des Comores (plantes vasculaires), famille 131. Firmin-Didot et cie., Paris, France. 537 pp. • Boiteau, P., Boiteau, M. & Allorge-Boiteau, L., 1999. Dictionnaire des noms malgaches de végétaux. 4 Volumes + Index des noms scientifiques avec leurs équivalents malgaches. Editions Alzieu, Grenoble, France.Other references• Missouri Botanical Garden, undated. VAST (VAScular Tropicos) nomenclatural database. [Internet] http://mobot.mobot.org/ W3T/Search/ vast.html. Accessed January 2010. • Schatz, G., undated. A catalogue of the vascular plants of Madagascar. [Internet]. Missouri Botanical Garden, St. Louis, United States. http://www.efloras.org/ flora_info.aspx?flora_id=12. Accessed September 2009. • Seyani, J.H., 1991. The genus Dombeya (Sterculiaceae) in continental Africa. Opera Botanica Belgica 2. National Botanic Garden of Belgium, Meise, Belgium. 186 pp. • Vololomboahangy, T.E.S., 2004. Attractions culturelles. In: Proposition d’un plan d’aménagement pour le développement de l’écotourisme dans les deux communes rurales d’Ambohimitombo et d’Antoetra dans la sous préfecture d’Ambositra Province autonome de Fianarantsoa. Mémoire de fin d’étude pour l’obtention du diplôme de maîtrise spécialisée en GRENE, Université de Toamasina, Madagascar. pp. 16–22.Author(s)